Conventionally, as one demand for a slide fastener that is opened and closed according to sliding of a slider, a configuration that prevents water or the like from entering through the slide fastener is demanded. As a configuration that prevents water or the like from entering through the slide fastener, there have been proposed a liquid-tight slide fastener (see Patent Document 1) in which an overlay material made from a synthetic resin is provided on one surface side of a fastener tape, and a water-repellent agent or an oil-repellent agent is attached to a core thread, a slide fastener (see Patent Document 2) in which the entire front and rear surfaces of a fastener tape are coated with an overlay material made from a synthetic resin, and the like.
The liquid-tight slide fastener disclosed in Patent Document 1 has a configuration as illustrated in FIG. 15. The liquid-tight slide fastener disclosed in Patent Document 1 is illustrated in FIG. 15 as a first conventional example of the invention, in which a configuration of a part of the liquid-tight slide fastener is depicted as a perspective view. As illustrated in FIG. 15, a liquid-tight slide fastener 50 has a configuration in which a coil-like coupling element row 53, through which a core thread 52 is inserted, is sewed along opposing side edges of a pair of left and right fastener tapes 51. Moreover, a liquid-tight layer 54 is formed on one surface of each of the pair of left and right fastener tapes 51.
Further, a water-repellent agent or an oil-repellent agent is attached to the core thread 52.
By configuring the liquid-tight slide fastener 50 in this manner, even when moisture or oil enter into a space portion of the coupling element row 53 from a coupling portion of the liquid-tight slide fastener 50, the entered moisture or oil can be repelled by the water-repellent agent or the oil-repellent agent attached to the core thread 52. Moreover, it is possible to prevent moisture or oil from penetrating further toward the inner side from the space portion of the coupling element row 53.
The slide fastener disclosed in Patent Document 2 has a configuration as illustrated in FIG. 16. The slide fastener disclosed in Patent Document 2 is illustrated in FIG. 16 as a second conventional example of the invention, in which a configuration of a part of one fastener stringer is illustrated as a perspective view. As illustrated in FIG. 16, a fastener stringer 60 includes a fastener tape 61 and an element row 64 that includes a plurality of element teeth 65 provided at an equal interval along a longitudinal direction of the fastener tape 61.
An overlay layer 66 made from an elastomer is formed on both front and rear surfaces of a core tape 62 and a projecting piece 63 that form the fastener tape 61, and an extension portion 67 made from the same material as the overlay layer 66 protrudes from the projecting piece 63. The thickness of the extension portion 67 is approximately the same as the thickness of the core tape 62 on which the overlay layer 66 is formed. Moreover, a flange 68 protrudes from the extension portion 67, and the flange 68 is made from the same material as the overlay layer 66 and has a thickness smaller than the thickness of the extension portion 67.
When a pair of element rows 64 engages with each other, the flanges 68 of the opposing fastener stringers 60 can be pressed and bent by intermeshing heads 65a of the element teeth 65. Moreover, when the flange 68 is bent, the whole circumference of the intermeshing head 65a is blocked by the flange 68.
As a result, a satisfactory liquid-tight state is created in the engaging portions of the engaged element teeth 65.